Message display system for television

ABSTRACT

A camera having a lens is positioned so that the lens has a predetermined line of view. An indexing unit is located at a position remote from said camera and selectively positions a plurality of cards into a position in which the cards on their images are viewable by the lens. Each card bears a written message. A clock or other viewable object is located remote from said indexing unit and is positioned so that it or its image may be viewed by said lens. In the preferred form the image from the cards or the clock is selectively positioned in the line of view of the lens by the selective rotation of a mirror. In modified forms the clock is directly in the lens line of view and the cards are selectively positioned into the lens line of view between the clock and the lens. In one modified form the cards are carried in an arcuate path about a horizontal axis whereas in the other modified form the cards are carried about a vertical axis. A control unit includes a system of various length tabs on the cards for breaking a light beam to one of three photocells. The tab length determines the length of time that a card is viewed and whether or not the mirror is rotated.

United States Patent [72] Inventors Milton K. Widdekind Seattle; William A. Lee, Puyallup, both of Wash. [21] Appl. No. 789,740 [22] Filed Jan. 8, 1969 [45] Patented Dec. 7, 1971 [73] Assignee Electronic Systems Development, Inc.

Seattle, Wash.

[54] MESSAGE DISPLAY SYSTEM FOR TELEVISION 6 Claims, 13 Drawing Figs.

[52] U.S. Cl 178/7.88, 40/28 C, 40/52 B, 40/78.09, 40/97, 178/DIG. 1 [51] Int. Cl H04n 5/24 [50] Field ofSearch.... 178/7.88, 7.89, 6, 7.2 ST; 40/78.07, 78.09, 36, 97, 28 C, 52 B [56] References Cited UNITED STATES PATENTS 3,239,601 3/1966 Keys 178/6 (IND) 3,461,228 8/1969 Bookman 178/7.2 ST 1,389,592 9/1921 Mather 40/97 X 1,967,843 7/1934 Sanders.. 40/97 X 2,152,495 3/1939 Otto 40/97 2,938,287 5/1960 Bernabei 40/36 3,110,976 11/1963 Wells et a1. 40/78.09

3,477,782 l1/l969 Sherwin 3,488,439 l/l970 Lairdetal.

ABSTRACT: A camera having a lens is positioned so that the lens has a predetermined line of view. An indexing unit is located at a position remote from said camera and selectively positions a plurality of cards into a position in which the cards on their images are viewable by the lens. Each card bears a written message. A clock or other viewable object is located remote from said indexing unit and is positioned so that it or its image may be viewed by said lens. In the preferred form the image from the cards or the clock is selectively positioned in the line of view of the lens by the selective rotation of a mirror. In modified forms the clock is directly in the lens line of view and the cards are selectively positioned into the lens line of view between the clock and the lens. In one modified form the cards are carried in an arcuate path about a horizontal axis whereas in the other modified form the cards are carried about a vertical axis. A control unit includes a system of various length tabs on the cards for breaking a light beam to one of three photocells. The tab length determines the length of time that a card is viewed and whether or not the mirror is rotated.

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PATENTED DEC 7 I97! SHEET '4 OF 4 MESSAGE DISPLAY SYSTEM FOR TELEVISION BACKGROUND OF THE INVENTION 1. Field of the Invention This invention pertains to information display systems for television or the like.

2. Description of the Prior Art There has been a need for a display system that is capable of sequentially exhibiting before a television camera various data for a particular class of viewers or the general public and particularly for exhibiting this information in a closed circuit television arrangement. One such apparatus is disclosed in the commonly assigned, copending application of Richard N. Sherwin, Ser. No. 617,574, filed Feb. 21, 1967, now US. Pat. No. 3,477,782, granted Nov. 1 l, 1969. In this system various data are positioned in the line of view of a TV camera by selectively illuminating one of the various data. More specifically a one-way mirror is positioned in the line of view of the lens and one information display unit containing the data is positioned in the same line behind the mirror. Another information display unit is positioned at an angle, that is, offset, to the line of view of the camera. The mirror is arranged so that when the first information display unit is illuminated the data is viewed through the mirror whereas when the offset information display unit is illuminated and the aligned unit is darkened the illuminated data from the offset unit is reflected by the mirror into the lens.

Prior to the above, the common practice for displaying desired information in a closed circuit television system was to arrange the various data in a line and then scan the line by intermittently moving the camera. Undesirable consequences of moving the camera are that the picture frequently is unsteady, the viewer is subjected to the somewhat unpleasant view of the background behind the data-bearing units, and an annoying movement of the data source appears as the camera scans from one source to the next.

SUMMARY OF THE INVENTION This invention pertains to a message display system of the type disclosed in said aforementioned application. A feature of this invention, however, is that it is much simpler in construction and consequently less expensive to manufacture. Primarily it utilizes the concepts of sequential display of numerous messages and alternately viewing a second object, such as a clock, but makes the selective transition from the messages to the second object by mechanical means in a much less complicated manner. In its broadest principle, the invention includes a camera having a lens with a predetermined line of view. An indexing unit having first data, such as a plurality of message holders, is positioned so that a message holder or an image of the message holder may be placed in the line of view. A second object, separate from the message holders, is positioned so that it or its image may be positioned in the line of view. Means are then provided for mechanically, selectively positioning one of these objects or its image into the lens line of view. In one form the selective positioning is done by a simple mirror and in modified forms the second object is positioned directly in the lens line of view and the first data is selectively positioned between the second object and the lens.

In the preferred form the illuminating lights for both the first and second objects or data are dimmed during movement of the mirror to reduce the likelihood of the viewer observing the movement.

Another feature is the control system for determining the length of time that the message holder or its image is to be in the line of view. The control system also enables rendering inactive the mirror for any particular message holder so that if desired a continuous message may be displayed by sequentially positioning a series of message holders into the line of view each message holder bearing a portion of the continuous message.

BRIEF DESCRIPTION OF THE DRAWing FIG. 1 is a schematic plan of the preferred form of the display system embodying the principles of the invention.

FIG. 2 is a side elevation of the system shown in FIG. I.

FIG. 3 is an isometric of a portion of the system shown in FIG. 1.

FIG. 3A is a schematic illustration of the various control conditions of the system shown in FIG. 1.

FIG. 4 is a schematic side elevation of the modified form of the invention of the type wherein the message holders are rotated about a vertical axis.

FIG. 5 is a fragmentary plan of the modified form shown in FIG. 4.

FIG. 6 is a fragmentary side elevation showing a message holder in a viewable position along the lens line of view.

FIG. 7 is a side elevation of still another modified form of the invention of the type in which the message holders are rotated about a vertical axis.

FIG. 8 is a plan of the modified form shown in FIG. 7.

FIG. 9 is a fragmentary side elevation of a portion of the system of FIG. 7.

FIG. 10 is a fragmentary side elevation of another portion of the system of FIG. 7.

FIG. II is a fragmentary end elevation of the portion of the system shown in FIG. 9.

FIG. 12 is a diagrammatic illustration of the control circuitry of the preferred form.

DESCRIPTION OF THE PREFERRED EMBODIMENTS In general the system of FIGS. l-3A and 12 comprises three major components, namely, a stationary, conventional television camera I2 having a lens 14, and indexing unit 18 carrying a plurality of first viewable objects, such as message holders 20 shown in FIG. 3, and a second object 16, such as a clock. The clock 16 is conventional and is stationary. As is readily understood, the lens is capable of viewing an image along a predetermined line of view. All of the components are mounted on a baseplate 21 which may be fitted on a cabinet, not shown.

Arranged in the lens line ofview is a conventional mirror 22 mounted on a conventional rotary solenoid 24. Upon receiving an electrical signal, the solenoid will rotate the mirror a few degrees such as between the solid and phantom line positions shown in FIG. I. When in the solid line position, the image received by the lens 14 will be that of a message holder 20 whereas in the phantom position the image received will be of the clock. Suitable tubular lights 26, one above and one below the mirror 22, provide illumination for the clock and the message holders. As is best shown in the circuit diagram of FIG. 12, the lights 26 are dimmed when the mirror is rotated so that the motion is not detected by the camera.

The indexing unit 18 comprises a pair of base members 30 each supporting a vertical side plate 32. The side plates are spaced from one another, as best shown in FIG. 1, and support a plurality of transverse shafts. A first transverse shaft 34 is secured in a side plate and to a conventional indexing motor 36 of the type that rotates a few degrees upon receiving an electrical signal. The shaft 34 is connected by a chain and sprocket 38 to a second shaft 40. A pair of chains 42 are entrained about sprockets fixed to the shaft 40 and also about sprockets fixed to a forward shaft 44. The lower runs of the chains 42 proceed downwardly about a. pair of sprockets fixed on a lower shaft 46 and then upwardly about a pair of sprockets fixed on a conventional takeup shaft 48. As best shown in FIG. 2, the chains are intermittently indexed in the clockwise direction as indicated by the arrow 49.

As best shown in FIG. 3, each of the message holders 20 are removably mounted in a carrier 50.. The carrier may be fabricated of metal, heavy cardboard, plastic or the like. In the preferred form, the carrier is molded of plastic and has lower and upper lips 52 and 54 respectively for slidably receiving the message holder 20. In the preferred form, the message holder is a card that is easily slipped into the lips 52 and 54 of the carrier. An abutment 56 is provided at one end of the carrier to position the card in the carrier and the card is held at the opposite end by a dimple 58. The carrier is provided with a positioning tab 60 that depends from its lower left-hand corner, as viewed in FIG. 3. The positioning tab is adapted to slide between a spring biased clip 64 and a vertical backing plate 65 that is secured to a forward end of the indexing unit. As will be described below, the carrier is moved past the clip 64 with the positioning tab 60 being pressed against the backing plate by the clip so as to hold the carrier in a vertical position while viewed by the lens 14.

Each of the carriers is provided with a transverse rod 66 that is rigidly mounted in the upper lip member 54. The chains 42 are each provided with a plurality of upright tongues 68 that are apertured to rotatably receive the rods 66. The rods are centered between the chains 22 and are secured against endwise movement by any suitable means. As is best shown in FIG. 2, the carriers are freely suspended between the chains during the lower course of travel and are overlapped as they are carried upward around the shaft 40.

For the purpose of carrying the carriers along the horizontal path at the top run of the chains, a horizontal plate 72 is provided between the vertical side plates 32. The horizontal plate 72 carries a pair of spaced, horizontal tubular guides 74 that run longitudinally of the indexing unit beneath the top run of each of the chains 42. The tubular guides prevent the chains from sagging and provide smooth guide surfaces for traversing the top of the indexing unit.

The message holders are carried across the top of the indexing unit face down and to the rear. It is therefore necessary to flip the carriers over before being viewed by the camera. For this purpose, each of the carriers is provided with a rounded cam surface 76 formed on the upper lip 54 of the carrier. A pin 78 is fixed to the side plate 32 and engages the cam surface as the chains 42 index the carriers to the right along the top of the indexing unit. The cam surface rides up over the pin pivoting the carrier 50 and flipping it over. After being flipped the lower lip 52 of the carrier 50 engages a stop member 80. With the next sequence of the motor 36 the carrier is lowered about the shaft 44, rides off the stop member 80, and falls into the vertical position in line with the mirror 22. When in the vertical position, the carrier is further indexed beneath the clip 64 so that it is held while in the position for viewing.

The sequence of flipping the carriers 50 is best illustrated by the use of the letters A, B, C and D. In position A a carrier is being engaged by the pin 78 and is about to be flipped into position B. In position B the carrier is suspended by the stop member 80. In position C the carrier is in the vertical position beneath the clip 64 so that the message holder image is projected on the mirror 22. In position D the carrier has moved downwardly out of engagement with the clip 64.

Each of the message holders carries a decal or otherwise removable surface having a message as indicated by the lines 82. Each message holder is also provided with a control tab 84. The control tabs 84, in conjunction with photocells and conventional circuitry, determine the length of time that the carrier is held in the viewing position C so that the message 82 may be viewed by the lens 14. The control tabs also determine whether the rotary solenoid 24 for rotating the mirror 22 should be deactivated. When deactivated a plurality of carriers may be positioned in position C without the mirror turning and thus without the image of the clock being projected to the lens 14. For these purposes, three photocells 85, 86 and 87 are secured to the sidewall 32 of the indexing unit directly behind the tabs of a carrier when in position C. A light source 88 is fastened to the baseplate 21 in a position to shine a light into the photocells. When a carrier is in position C, that is, its image is projectable into the mirror 22, one or more of the photocells are screened from the light source by the control tab 84. The system, as controlled by the control tabs 84, has five conditions which are regulated by the presence of a control tab and the length of the control tab. As best shown in FIG. 3A, the five conditions are as follows: i

Condition I is with no control tab 84 to cover any of the photocells 85, 86 or 87. This is the condition when no message holder is in the carrier. In this condition the indexing motor continues to rotate so as to bypass that carrier. The mirror will remain in the phantom position shown in FIG. 2 so that the image of the clock 16 is in the lens 14 and there will be no delay of the carrier through position C. In Condition II, the shortest control tab 84 is shown covering photocell 85. In this condition the normal sequencing of the motor 36 takes place with a delay of 13 seconds while a carrier is in position C. Prior to the l3 second delay, the mirror 22 is rotated into the solid line position so that thc'image of the message holder in position C is projected into the lens 14. At the end of the 13 second delay the mirror is rotated back into the phantom position to cast the image of the clock into the lens 14. In condition III, two of the photocells are covered by a control tab. In this condition the delay time is doubled to 26 seconds with the sequencing of the indexing motor 36 and the position of the mirror 22 being identical with the condition II. In condition IV (long card condition), all three of the photocells are covered. In this condition a 26 second delay takes place because photocell 86 is covered but the rotary solenoid to the mirror is deactivated so that at the end of the 26 second delay the next carrier 50 is positioned in position C without the image of the clock 16 being projected into the lens 14. In this condition, a continuous message requiring the entire space of several message holders 20 may be.displayed without the interruption of the clock 16. The image displayed on the television screen will be of the message holder 20 bearing the first part of the continuous message, the viewer will then see the second card being carried into position C where the message will be continued and so on until the desired message is completed. In condition V, the photocells and 87 are covered but a hole is placed in the tab in alignment with photocell 86. In this condition a l3 second delay occurs but the rotary solenoid is inactivated as in condition IV.

FIG. 12 is a diagrammatic illustration of the circuitry for carrying out the controls illustrated in FIG. 3A. The circuitry may readily be developed by one skilled in the art. For this reason the details of the circuit will not be described.

In FIGS. 4, 5, and 6 a modified form of the display system is illustrated. In this form the message holders are removable held in carriers 101 that are pivotally mounted by a pin 102 on a horizontal platform 104. The horizontal platform is rotatably mounted on a post 106 and is rotated by an indexing motor 108 similar to the indexing motor 36 of the preferred embodiment. A circular flange 110 is secured to the underside of the horizontal plate and is engaged by a rubber roller 112 that is secured to the rotary shaft of the indexing motor 108. A clock 114 is positioned directly in the line of view of the lens 116 of a camera 118. The clock, lens and camera are above the plane of the message holders 100 when suspended from the horizontal platform 104. In order to bring a message holder into view of the lens, it is necessary to raise it as shown in solid lines in FIG. 6. In this position the message holder is between the clock and the camera so that the selective viewing of the clock and message holders are controlled merely by raising the carrier 101. In order to raise the carrier 101 and thus the message holder 100 into the upper position as shown in FIG. 6, a cam 120 having a roller 122 is pivoted for oscillation about a horizontal pin 124. The cam 120 has an actuating end with a roller 126 that is engaged by an eccentric cam 128 rotated by a motor 130. When a carrier 101 is in a position in alignment with the roller 122 the rotation of the horizontal platform 104 is stopped and the motor 130 is energized to move the cam 120 in a clockwise direction. The roller 122 then pushes against the underside of the carrier 101 raising it into the position shown in FIG. 6. After the desired delay time, such as 13 or 26 seconds as in the preferred embodiment, the motor 130 is again energized lowering the cam and the carrier into the position shown in FIG. 4. At this time the clock will be in the lens line of view and the horizontal platform 104 is again indexed by the indexing motor 108 to bring the next carrier and message holder into position to be raised.

In the modification shown in FIGS. 7-11, the principle of interposing the message holder between the lens and clock is again employed; however, the message holders are moved about a horizontal axis rather than about a vertical axis. A clock 140 is positioned directly in line with the lens 142 of camera 144 and thus will be viewed by the camera except in those conditions when a message holder is interposed between the lens and the clock. The indexing unit 146 of this modification includes a pair of spaced frame plates 148. Rotatably mounted in the plates is a shaft 150 that is rotated by an indexing motor 152 similar to the indexing motor 36 of the preferred embodiment. A pair of spaced arms 154 are keyed to the shaft 150 for rotation therewith. Each of the arms rotatably mounts a pin 158 at either end. A retaining clip 156 is secured to each pin. The free end of each pin 158 is secured to a sprocket 160. A chain 162 is entrained about the sprocket 160 and about an idler sprocket 164 that is fixed relative to the vertical plates 148. A parallelogram linkage is thus established such that upon rotation of the arms 154 the clips will be moved in a circular path but their orientation will be unchanged due to the connection with the chains 162.

As best shown in FIGS. 9 and 10, each clip includes a pickup surface 164, a V or valley 166, and a discharge surface 168. The discharge and pickup surfaces are employed to replace and remove the carriers 170 from a stack indicated generally by the reference character 172. The carriers 170 are generally identical to the carriers 50 of the preferred embodiment and include a message holder 172 and a transverse rod 174. A second transverse rod 175 is added to the lower end of each carrier. The message holders are stored in the stack 172 with the written message in the upper position. As the arms make their circular traverse, the clips 156 are brought into line with the transverse rods 174 of the lowermost carrier 170 in the stack. As is best shown in FIG. 10, the carriers are supported in the stack by a pair of spaced bolts 176 and small spaced ledges 178. As the arms are rotated the pickup surfaces 164 of the pair of clips 156 engage the upper transverse rod 174 of the lowermost carrier 170 in the stack. As the arms continue the pickup surfaces push the carrier off the bolts 176 and the small ledges 178 so that the carrier falls into the V 166 in the vertical position as shown in phantom lines in FIG. 7.

The sequence is best illustrated with letters A-E. In position A the carriers are in the stack 172. In position B a carrier is removed and is hanging in the vertical position. When the motor 148 is again indexed, the arms are raised so that the carrier is moved into a position C in line of view of the lens 142. The arms then progress to a position D and the clock 140 is again in the lens line of view. In position E the carrier 170 is again placed on the stack 172. This is accomplished by a pair of spaced, pointed ears 180 engaging the tops of the carrier to cause the transverse rod 174 to ride up on the discharge surface 168 of the clips 156 as the clips are moved in their arcuate paths. Further movement will release the support rods 174 and the carrier is then dropped into the stack and the clips are moved downwardly to the position to pick up the lowermost carrier of the stack.

While several modifications of the invention have been illustrated, the invention is not to be construed as limited to the particular forms disclosed herein, since these are to be regarded as illustrative rather than restrictive.

What is claimed is:

1. A message display system for television or the like, comprising:

a. a camera having a lens;

b. an indexing unit having a plurality of message holders selectively and successively movable to a position in alignment with said lens and movable to a position out of alignment with said lens, said indexing unit including a horizontal platform, a plurality of carriers for supporting said message holders pivotally secured to said platform, and means for intermittently rotating said platform;

c. a second viewable object aligned with said lens, said message holders when aligned with said lens being between said lens and said second viewable object, said message holders when not aligned with said object leaving an unobstructed line of sight from said lens to said second viewable object, and

d. control means for selectively moving each message holder into such aligned position and out of aligned position to leave an unobstructed view of the second viewable object, said control means including actuating means for raising a carrier into said aligned position.

2. The message display system defined by claim 1, wherein said actuating means includes a cam pivotally mounted on a horizontal pin, one end of said cam having a roller engageable with said carrier and the other end having a roller engageable with a motor-driven eccentric cam.

3. A message display system for television or the like, comprising:

a. a camera having a lens;

b. an indexing unit having a plurality of message holders selectively and successively movable to a position in alignment with said lens and movable to a position out of alignment with said lens, said indexing unit including a pair of spaced, opposed anns rotatably mounted about a horizontal axis; a plurality of carriers for supporting said message holders, each of said carriers having a transverse rod; a clip rotatably mounted at each end of said arms for securing and supporting said transverse rod of a carrier; means for placing carrier in a supported position with said clips, means for holding said clips in a constant vertical orientation, and means for discharging said carriers from out of said clips after leaving said position aligned with said lens;

or a second viewable object aligned with said lens, said message holders when aligned with said lens being between said lens and said second viewable object, said message holders when not aligned with said object leaving an unobstructed line of sight from said lens to said second viewable object, and

(I. control means for selectively moving each message holder into such aligned position and out of aligned position to leave an unobstructed view of the second viewable object.

4. The message display system defined by claim 3, wherein said means for holding said clips in a constant vertical orientation further includes a pair of inner sprockets fixed along said horizontal axis, a pair of outer sprockets mounted for rotation with said clips on adjacent ends of said opposed arms and a pair of chains each entrained about said inner and outer sprockets.

5. The message display system defined by claim 4, wherein said carriers each includes a second transverse rod and said in dexing unit further includes a stack holder having a pair of opposed bottom support pins and a pair of short ledges for supporting a carrier by its transverse rods.

6. A message display system for television or the like comprising:

a. a camera having a predetermined line of view;

b. an indexing unit having a plurality of movable message holders selectively presentable in a viewable position;

c. first moving means to move said message holders selectively to said viewable position;

d. a stationary viewable object at a position angularly offset from said indexing unit and out of said line of view;

e. reflective means in said line of view and selectively movable into a first position wherein one of said movable message holders in said viewable position is reflected into said line of view and a second position whereby said stationary viewable object is reflected into said line of view;

f. second moving means to move said reflective means between its first and second positions; and

g. control means to cause sequential viewing of said message holders and said stationary viewable object, said control means comprising:

1. means for activating said second moving means to move said reflective means from its first position to its second position,

2. means for deactivating the second moving means so that the reflective means remains in its second position to cause the stationary viewable object to be reflected into the line of view of the camera,

3. means for activating said first moving means to move a 4. means for deactivating said first moving means for a predetermined delay period, to hold said first message holder in its viewable position during said delay period,

5. means for activating said second moving means at the initial portion of said delay period to move said reflective means back to its first position,

6. means for deactivating said second moving means for the duration of said delay period whereby said first message holder remains in the line of view of the camera during the delay period, and

7. means for recycling the control means (6) with respect to a second message holder of the indexing unit; and

h. said control means further comprises:

1. a plurality of photo cells,

2. a light source to activate said photo cells, and,

3. a plurality of tab means, each mounted to respective message holders, each of said tab means being arranged to cover selected photo cells so as to determine the steps initiated by said control means.

I i U i l 

1. A message display system for television or the like, comprising: a. a camera having a lens; b. an indexing unit having a plurality of message holders selectively and successively movable to a position in alignment with said lens and movable to a position out of alignment with said lens, said indexing unit including a horizontal platform, a plurality of carriers for supporting said message holders pivotally secured to said platform, and means for intermittently rotating said platform; c. a second viewable object aligned with said lens, said message holders when aligned with said lens being between said lens and said second viewable object, said message holders when not aligned with said object leaving an unobstructed line of sight from said lens to said second viewable object, and d. control means for selectively moving each message holder into such aligned position and out of aligned position to leave an unobstructed view of the second viewable object, said control means including actuating means for raising a carrier into said aligned position.
 2. The message display system defined by claim 1, wherein said actuating means includes a cam pivotally mounted on a horizontal pin, one end of said cam having a roller engageable with said carrier and the other end having a roller engageable with a motor-driven eccentric cam.
 2. means for deactivating the second moving means so that the reflective means remains in its second position to cause the stationary viewable object to be reflected into the line of view of the camera,
 2. a light source to activate said photo cells, and,
 3. a plurality of tab means, each mounted to respective message holders, each of said tab means being arranged to cover selected photo cells so as to determine the steps initiated by said control means.
 3. means for activating said first moving means to move a first selected message holder of the indexing unit into its viewable position after said reflective means has moved from its first position,
 3. A message display system for television or the like, comprising: a. a camera having a lens; b. an indexing unit having a plurality of message holders selectively and successively movable to a position in alignment with said lens and movable to a position out of alignment with said lens, said indexing unit including a pair of spaced, opposed arms rotatably mounted about a horizontal axis; a plurality of carriers for supporting said message holders, each of said carriers having a transverse rod; a clip rotatably mounted at each end of said arms for securing and supporting said transverse rod of a carrier; means for placing carrier in a supported position with said clips, means for holding said clips in a constant vertical orientation, and means for discharging said carriers from out of said clips after leaving said position aligned with said lens; c. a second viewable object aligned with said lens, said message holders when aligned with said lens being between said lens and said second viewable object, said message holders when not aligned with said object leaving an unobstructed line of sight from said lens to said second viewable object, and d. control means for selectively moving each message holder into such aligned position and out of aligned position to leave an unobstructed view of the second viewable object.
 4. The message display system defined by claim 3, wherein said means for holding said clips in a constant vertical orientation further includes a pair of inner sprockets fixed along said horizontal axis, a pair of outer sprockets mounted for rotation with said clips on adjacent ends of said opposed arms and a pair of chains each entrained about said inner and outer sprockets.
 4. means for deactivating said first moving means for a predetermined delay period to hold said first message holder in its viewable position during said delay period,
 5. means for activating said second moving means at the initial portion of said delay period to move said reflective means back to its first position,
 5. The message display system defined by claim 4, wherein said carriers each includes a second transverse rod and said indexing unit further includes a stack holder having a pair of opposed bottom support pins and a pair of short ledges for supporting a carrier by its transverse rods.
 6. A message display system for television or the like comprising: a. a camera having a predetermined line of view; b. an indexing unit having a plurality of movable message holders selectively presentable in a viewable position; c. first moving means to move said message holders selectively to said viewable position; d. a stationary viewable object at a position angularly offset from said indexing unit and out of said line of view; e. reflective means in said line of view and selectively movable into a first position wherein one of said movable message holders in said viewable position is reflected into said line of view and a second position whereby said stationary viewable object is reflected into said line of view; f. second moving means to move said reflective means between its first and second positions; and g. control means to cause sequential viewing of said message holders and said stationary viewable object, said control means comprising:
 6. means for deactivating said second moving means for the duration of said delay period whereby said first message holder remains in the line of view of the camera during the delay period, and
 7. means for recycling the control means (6) with respect to a second message holder of the indexing unit; and h. said control means further comprises: 